Seaside Birds-foot Trefoil (Lotus formosissimus) Global: G4 Provincial: S1 COSEWIC: E, BC List: Red
Note on Taxonomy for Lotus formosissimus: This rare member of the Fabaceae (pea) family, also referred to as seaside lotus (E-Flora, USDA Plants database) overlaps with number of other trefoil species in BC.
Distribution: This species occurs along maritime meadows and headlands from California to southeast British Columbia. On the Coast Region it has a very limited distribution with only 5 of the historic 6 populations in the Greater Victoria and adjacent islands remaining. Within these locations 4 are clustered around the maritime headlands of the Esquimalt area (mainly on Department of National Defence Lands) and one isolated group of 28 plants to the east on Trial Island Ecological Reserve. The harsh seaside habitat niche of this species limits populations to relatively small numbers of plants (GOERT 2002, Parks Canada 2006).
Description: Height 200-500A perennial ground spreading herb growing from a rhizome, reaching 20-50 cm tall, usually sprawling but occasionally erect. Stems are multi-branched and without hairs.
Leaves: Stem leaves alternate in arrangement, divided into five (occasionally three or seven) oppositely arranged leaflets. Leaflets egg- or spoon-shaped, 6-20 mm long. Large, triangular stipules present.
Flowers: Inflorescence has a long stalk with a compact cluster of 3-9 pea-like flowers; a delicate bract divided three times is present just below the flowers. Corollas generally yellow with distinct pink to purple wings.
Fruits and seeds: pea-like pod, 2-4 cm long, with up to 15 dark brown or black seeds.
Look’s Like? May be confused with the more common meadow birds-foot trefoil. It can be distinguished from the seaside birds-foot trefoil by the fine hairy stems and leaves, the creamy-white and purplish corollas, and the presence of a taproot instead of a rhizome.
Primary Habitat: as with many marine headland and Garry oak meadow species this annual is tolerant of continuous sun, wind and salt spray and favours southern, eastern or northeastern aspects. Other associated native wildflowers include broad-leaved shooting star and common camas (in moist upper slope areas). These communities also tend to contain large amounts of invasive alien pasture grasses such as orchard-grass and brome species (Parks Canada 2006)
Secondary Habitat: Populations also occupy seasonal seepages that occur on slightly sloping exposed rocky outcrops along the shoreline that dry up toward the end of summer.
Critical Features: Bearded owl-clover is distinctly shade intolerant and is usually found growing within shallow damp to wet soils in shortgrass/forb communities that form headland meadows and grasslands near the ocean.
Seasonal Life Cycle
*Re-sprouting can occur after summer/fall drought periods if late summer rains occur (rarely occurs). Dormant buds may break as early as September with new shoots emerging from the soil by late September or early October.
Habitat Guild: Sea level to low elevation wildflower meadows, Garry Oak woodlands and marine bluffs, rock outcroppings and seeps.
The preferred ecological associations of this species are geographically limited and subject to urban development and associated habitat loss.
This species is subject to high seedling mortality, few plants survive their first summer die-back. Remaining plants are slow to regenerate and do not flower in their year of germination nor is clear how long plants take to flower.
Disturbance and trampling from outdoor recreation activities.
Competition for nutrients and shading from associated vascular plants and subsequently expansion of other more shade tolerant species.
Fire suppression has led to increased spread and encroachment of competitive plant species (i.e. vascular plants) including several invasive species.
Grazing by livestock has contributed to decline of at least one population.
Key Conservation & Management Objectives
Assess actual level and extent of threats to existing populations.
A targeted inventory is needed to determine if undiscovered populations exist elsewhere within the Coast Region and to assess the status of all known populations.
Monitor existing populations on an ongoing basis to assess viability and reduce potential disturbance from land use activities. Where suitable habitat occurs, work with land managers and land owners to ensure development or recreational activities do not disturb or encroach on sensitive areas.
Consider historic distribution as part of developing a reintroduction program to suitable sites.
Conduct outreach to raise awareness of this species and how to identify it to improve distribution knowledge
Prevent the introduction and spread of invasive plants, especially aggressive competitors like Scotch broom and Himalayan blackberry, which can be difficult to control once they are established. When controlling invasive plants, take precautions to minimize disturbance.
Meet objectives for this species and the conservation of its habitat as set out in the “Recovery Strategy for Multi-species at Risk in Maritime Meadows Associated with Garry Oak Ecosystems in Canada”.
Sightings, specimens, or observations of activities threatening its habitat should be reported to the regional Species at Risk Biologist at the Ministry of Environment office.
Main References/Literature Cited
Parks Canada Agency. 2006. Recovery Strategy for Multi-species at Risk in Maritime Meadows Associated with Garry Oak Ecosystems in Canada. In Species at Risk Act Recovery Strategy Series. Ottawa: Parks Canada Agency. 93 pps.
Species at Risk in Garry Oak and Associated Ecosystems in British Columbia. 2002. Lotus formosissimus Garry Oak Ecosystems Recovery Team.
International Forest Products Limited and BC Ministry of Environment. 2003. A Field Guide to Species at Risk in the Coast Forest Region of British Columbia
Develop With Care: Environmental Guidelines for Urban and Rural Land Development in British Columbia.
BC Species & Ecosystems Explorer (BC Conservation Data Center Summary Report)
Committee on the Status of Endangered Wildlife in Canada
E-Flora Electronic Atlas of the Plants of British Columbia
USDA, NRCS. 2010. The PLANTS Database
Seaside Birds-foot Trefoil: Larry McCombs
Seaside Birds-foot Trefoil inset: Stan Shebbs
Meadow Birds-foot trefoil: Jean Pawek
Habitat: Calypso Orchid (Flickr)
Disclaimer: This species account and related conservation recommendations are draft only and presently under review and subject to change.